I thought I’d share my favourite (and what I believe are the most useful) jQuery plugins out there. There are tonnes of plugins available though, so if you’re looking for something particular then check out Google and the offical jQuery plugins website. If you want to have a go at building your own jQuery plugin then check out this guide ("Developing a jQuery plugin") written by Jonathan Snook.

In no particular order:

• 

  jQuery UI

  jQuery UI is great for developing and enhancing online applications. It enables your web app to behave like a desktop app! Perfection!

  jQuery UI provides abstractions for low-level interaction and high-level, themeable widgets, built on top of the jQuery JavaScript Library, that you can use to build highly interactive web applications.

  See "tabs" demo »
  See "splitpane" demo »
  See "photo-manager" demo »

• 

  Mark-It-Up

  I haven’t used this plugin yet but it looks absolutely awesome! There are quite a few textarea enhancers out there! Example code: $('#html').markItUp(myHtmlSettings);

  markItUp! is a JavaScript plugin built on the jQuery library. It allows you to turn any textarea into a markup editor. Html, Textile, Wiki Syntax, Markdown, BBcode or even your own Markup system can be easily implemented.

  See a demo »

• 

  jQuery cookie plugin

  The cookie plugin (by Klaus Hartl) allows you to easily set, get and delete cookies. It’s particularly useful for when you need to save a user preference for future visits to your site. For example, if you’re creating a user StyleSheet switcher then you’d need cookies to store the user’s preference. Example code: $.cookie('cookieName', 'value')

  See a demo »

• 

  lightbox for jQuery

  The popular prototype lightbox plugin has been ported (by Warren Mesozen) to jQuery and still retains it’s smooth enlargement animation. Example code <a href="images/image-1.jpg" rel="lightbox" title="my caption">image #1</a>

  Check out this version too; it’s basically the same but the enlargement animation is slightly different.

  See a demo »

• 

  jQuery Corner Plugin

  A very useful plugin for creating a range of corners on the fly. I’ve never tried out JavaScript corners, but if I were to I would definitely check out this plugin! Example code: $(this).corner();

  The corner function takes one string argument: $().corner("effect corners width") The effect is the name of the effect to apply, such as round or bevel. If you don’t specify an effect, rounding is used. The corners can be one or more of top, bottom, tr, tl, br, or bl. By default, all four corners are adorned. The width specifies the width of the effect; in the case of rounded corners this will be the radius of the width. Specify this value using the px suffix such as 10px, and yes it must be pixels.

  See a demo »

• 

  jTip

  A cool tooltip plugin. Unlike the alternatives jTip can get it’s data using AJAX! Example code: class="jTip"

  jTip pulls content into a tool tip using the HttpXMLRequest object. By adding a class attribute value of “jTip” to a link element you can create a tooltip from the content found in the file the href is pointing too. Also jTip can be customized by providing user defined widths (defaults to 250px wide) via a URL query string. The height is liquid and stretches to match the content that fills the tool tip. Additionally it’s possible to provide a link (via URL query string) to a jTip tool tip link element (a href) so that the link will still function as expected by the user.

  See a demo »

• 

  LavaLamp

  A clever plugin which adds a smooth slide effect to your CSS menus. I really like this effect, although I can imagine it getting over-used a bit. Example code: $(".lavaLamp").lavaLamp({})

  Hover and feel for yourself, the nifty effect of Lava Lamp. What you just experienced is nothing but the LavaLamp menu packaged as a plugin for the amazing jQuery JavaScript library. I personally believe that the effect rivals that of flash - Don’t you? Especially considering the fact that it is extremely light weight. Just so you know, it weighs just 700 bytes(minified)!

  See a demo »

• 

  Superfish

  A highly accessible navigation menu (which degrades perfectly) enhanced with jQuery’s animation capabilities. It definitely makes the list for it’s ease of use and cleanliness! Example code $("ul.nav").superfish({});

  See a demo »

• 

  jQuery easing plugin

  Instead of spending hours developing your own animations using jQuery why not download the "easing" plugin; all the legwork has been done for us!

  A jQuery plugin from GSGD to give advanced easing options. Uses Robert Penners easing equations for the transitions.

  See a demo »

• 

  jCarousel

  I haven’t used jCarousel on a project yet but it looks awesome! Example code: jQuery('#mycarousel').jcarousel();

  jCarousel is a jQuery plugin for controlling a list of items in horizontal or vertical order. The items, which can be static HTML content or loaded with (or without) AJAX, can be scrolled back and forth (with or without animation).

  There is a “lite” version available too - jCarousel-Lite.

  See a demo »